Ten cakes cost £3.50 how much do three cakes cost?

Assuming that all 10 cakes are of same price,

first step is to find the cost of one cake, divide by 10

3.50:10=0.35

second is to find 3 cakes, multiply cost of one cake by 3

0.35x3=1.05

therefore, the price of 3 cakes is £1.05